Seasonal Changes in Forage Nutrients and Mineral Contents in Water Resources,Forage and Yak Blood

This paper reports results of a study conducted to investigate the concentrations of seven mineral elements in yak blood, forage and water resources around the Qinghai Lake in Qinghai Province in different seasons. Meanwhile, the nutritional compositions of the forage were also surveyed. The results suggest that the mineral elements and the forage nutrients change in a seasonal pattern. In yak blood,the sodium(Na)concentration varies from 0.291 to 0.034 mg/mL,and this is lower than the normal value. In the forage,the ratio calcium(Ca)to phosphorus(P)is 4.06～7.47:1 and potassium(K)to Na 30～27:1. These results indicate that the nutrition of the yak in the area is deficient in Na but high in K. For the withered forage sampled in February,the protein content is only 31.14% of the total protein in the forage growing at puerile stage in June. The severe loss of protein by 68. 9% and decrease of effective nutrients in the wintered forage are considered to be the reasons resulting in the poor condition of yak in winter and spring seasons.     

Variation in needle longevity of Pinus tabulaeformis forests at different geographic scales

Needle longevity of conifer species is known to increase with latitude, but little is known about intraspecific variation and associated factors within a location. Chinese pine (Pinus tabulaeformis Carr.) forests were investigated to identify patterns of needle longevity at seven sites with distinctive climatic conditions along a latitudinal gradient (33-38 degrees N) in Shaanxi province, northwest China. A demographic approach was used to quantify needle longevity as an index of entire foliage population adjusted to needle-age-specific mortality rates. There were significant differences in needle longevity of Chinese pine stands across sites and across sample plots within a site. Individual tree needle longevity ranged from 0.62 to 3.75 years for 276 samples across sites. Needle longevity increased with latitude (R2 = 0.40, P < 0.0001), but decreased with mean January temperature (R2 = 0.63, P < 0.0001). Foliage retention of Chinese pine stands at the regional level was generally associated with climatic variability, indicating that variation in needle longevity was primarily an environmental acclimation to low temperature in winter. Stand characteristics were closely associated with needle longevity at three sites located within the same climatic zone. Needle longevity was positively correlated with tree age (R2 = 0.48, P < 0.0001) and stand density (R2 = 0.26, P = 0.0015) at Huanglong and Huangling, respectively, whereas it was negatively associated with total tree height at Zhidan (R2 = 0.50, P < 0.0001). It is concluded that, at the stand and individual tree level, intraspecific variation in needle longevity is most likely a result of adaptation to patchy microsite environments.     

大鼠蛛网膜下腔出血后皮质中VDAC1的表达与神经元凋亡的关系

目的 观察大鼠蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后大脑皮质中VDAC1表达和皮质神经元凋亡,以及两者之间的关系,探讨电压依赖性阴离子通道蛋白1(voltage-dependent anion channel1,VDAC1)参与SAH后早期脑损伤的发生机制.方法 将SD大鼠108只按随机数字表法分为假手术组(n=18只)和SAH组(n=90,下设SAH后6、12、36、48、72 h5个时相点,每个时相点18只).采用视交叉前池注血法建立SAH模型,应用RT-PCR、免疫组化和Western blot分别检测大鼠SAH后不同时相点VDAC1在mRNA水平、蛋白质水平的表达变化.凋亡原位末端标记法( Tunel)观察SAH后不同时相点大脑皮质神经元凋亡.结果 大脑皮质中VDAC1表达,无论在mRNA水平,还是在蛋白质水平,在SAH后12 h均明显增加[mRNA(2.40 ±0.19),蛋白(1.14±0.08)],于36 h时表达达最高峰[mRNA( 3.40±0.65),蛋白(1.72±0.22)],于48 h开始下降[mRNA( 1.94±0.30),蛋白(0.97±0.07)],至72 h时基本恢复正常(P＞0.05).TUNEL法检测显示大鼠SAH后12 h,大脑皮质中神经元凋亡细胞数开始增加,36 h达到高峰,之后逐渐降低(P＜0.05),72 h时降至正常(P＞0.05).结论 SAH后不同时间点VDAC1表达水平的动态变化与神经元凋亡发生、发展的时相性是一致的,提示VDAC1可能通过细胞凋亡途径参与SAH后早期脑损伤的病理过程.     

Effect of recombinant canine IFNγ on canine atopic dermatitis evaluated by clinical signs,histopathology and expression of Th1/Th2 cytokine mRNA

Atopic dermatitis (AD) is thought to be caused by immunologic abnormalities expressed as a Th1/Th2 cytokine imbalance in both humans and dogs. Several studies have focused on the therapeutic effects of IFNγ in human AD with successful results; however, the mechanism of action of IFNγ is not fully understood. We investigated the effect of recombinant canine interferon gamma (rCaIFNγ) on 10 dogs with AD and evaluated the ratio of IL‐4 mRNA to IFNγ mRNA in peripheral blood mononuclear cells, serum total IgE levels, and histological changes in skin. After six injections of rCaIFNγ over a span of 2 weeks, seven of the 10 dogs showed improvement, and six of these seven dogs exhibited decreased IL‐4:IFNγ mRNA ratios. Two of the three cases that did not improve had increased IL‐4:IFNγ mRNA ratios. Total serum IgE levels were significantly decreased in nine of 10 cases. The number of IgE‐positive cells detected by immunostaining and the number of mast cells in skin biopsy samples were decreased. A reduction of epidermal cell layers was demonstrated by histopathology after treatment. These results demonstrated that rCaIFNγ may be a novel safe and effective therapeutic option for the treatment of canine AD, and the mechanism of action of rCaIFNγ may be related to the modulation of Th2 cytokines to Th1 cytokines with the reduction of serum IgE production. Funding: Self‐funded.     

Molecular cloning of equine chromogranin A and its expression in endocrine and exocrine tissues

Chromogranin A (CGA) is a member of a family of highly acidic proteins co-stored and co-released with catecholamines in the adrenal medullary cells as well as in other neurons and paraneurons. The nucleotide sequence encoding equine CGA was determined using RT-PCR and rapid amplification of complementary DNA (cDNA) ends (RACE) techniques. A total 1,828 bp of the nucleotide sequence reveals that equine CGA is a 448-residue protein preceded by an 18-residue signal peptide. Comparison of the amino acid sequence of equine CGA with those of human, porcine, bovine, mouse, rat and frog CGA showed high conservation at the NH2-terminal 1-77 amino acids regions (94.8%, 93.5%, 92.2%, 81.8%, 83.1% and 66.2%, respectively) and COOH-terminal 314-430 amino acids regions (90.6%, 81.4%, 90.6%, 80.5%, 83.3% and 39.0%, respectively), as well as a potential dibasic cleavage site, whereas the middle portion showed marked sequence variation (52.5%, 49.1%, 38.9%, 26.6%, 27.9% and 6.2%, respectively). Northern blot analysis and RT-PCR elucidated the tissue distribution of equine CGA mRNA. Its expression was confirmed not only in the adrenal medullary cells but also in other organs (cerebrum, cerebellum, pituitary gland, spinal cord, liver, thyroid gland, striated muscle, lung, spleen, kidney, parotid gland and sublingual gland). Further, in adrenal chromaffin cells and pituitary cells of the anterior-intermediate lobe, the expression was confirmed by in situ hybridization with anti-sense CGA cRNA probe.